Browsing by Author "Simpson, B R S"

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    A new liquid scintillation counting technique to resolve mixtures of two pure beta-emitting radionuclides
    (2007) Van Wyngaardt, Winifred Margaret; Simpson, B R S; Jackson, Graham Ellis
    Methods currently available for the accurate activity resolution of dual-label solutions of pure β-emitting radionuclides are mostly time consuming and involve much effort. The goal of this thesis was therefore to devise a simpler method to achieve the same objective. The technique developed is based on elements of two liquid scintillation counting techniques that are widely used to measure single-radionuclide solutions, namely the triple-to-double coincidence ratio (TDCR) efficiency calculation technique and the CIEMAT/NIST efficiency tracing method. Double- and triple-coincidence count rates, together with the figure-of-merit P determined from an external tracer, provide sufficient information to extract the component activities of a source in a simple manner.
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    Polarization in neutron-proton elastic scattering at 21.6 MEV
    (1986) Simpson, B R S; Brooks, F D
    The polarization in n-p scattering has been measured at 21.6 MeV using polarized neutrons from the T(d,ṅ)4He reaction. The measuring instrument was an anthracene scintillation polarimeter. A critical assessment of this polarimeter was made, and extensive refinements to the polarimeter were introduced so as to minimise perceived sources of systematic error. These included improvements both in instrumental design and data reduction techniques.